US10523720B2 - P-CSCF recovery and reregistration - Google Patents

P-CSCF recovery and reregistration Download PDF

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Publication number
US10523720B2
US10523720B2 US15/553,259 US201515553259A US10523720B2 US 10523720 B2 US10523720 B2 US 10523720B2 US 201515553259 A US201515553259 A US 201515553259A US 10523720 B2 US10523720 B2 US 10523720B2
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Prior art keywords
cscf
reregistration
secure association
security token
registration
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US20180241784A1 (en
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Magnus Hallenstål
Fredrik Lindholm
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Telefonaktiebolaget LM Ericsson AB
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Telefonaktiebolaget LM Ericsson AB
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
    • H04L65/1066—Session management
    • H04L65/1073—Registration or de-registration
    • H04L65/1006—
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
    • H04L65/10—Architectures or entities
    • H04L65/1016—IP multimedia subsystem [IMS]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
    • H04L65/10—Architectures or entities
    • H04L65/1045—Proxies, e.g. for session initiation protocol [SIP]
    • H04L65/105—
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
    • H04L65/1066—Session management
    • H04L65/1101—Session protocols
    • H04L65/1104—Session initiation protocol [SIP]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
    • H04L65/80—Responding to QoS
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00—Network arrangements or protocols for supporting network services or applications
    • H04L67/01—Protocols
    • H04L67/10—Protocols in which an application is distributed across nodes in the network
    • H04L67/1001—Protocols in which an application is distributed across nodes in the network for accessing one among a plurality of replicated servers
    • H04L67/1034—Reaction to server failures by a load balancer
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/04—Key management, e.g. using generic bootstrapping architecture [GBA]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/04—Key management, e.g. using generic bootstrapping architecture [GBA]
    • H04W12/041—Key generation or derivation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/06—Authentication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/06—Authentication
    • H04W12/062—Pre-authentication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/06—Authentication
    • H04W12/069—Authentication using certificates or pre-shared keys
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/04—Arrangements for maintaining operational condition

Definitions

  • the invention relates to recovery in an IMS network, and in particular to methods for recovery and reregistration of a P-CSCF, and to nodes implementing such methods.
  • UEs user equipments
  • IMS IP Multimedia Subsystem
  • P-CSCF Proxy Call Session Control Function
  • the P-CSCF is the contact point between the IMS and the UE, i.e. all communications between the UE and the IMS are routed via the P-CSCF to which the UE is registered. Therefore, any malfunction of the P-CSCF will cause a loss of service for UEs registered to the P-CSCF.
  • One possible failure mode of the P-CSCF is the loss of the secure association with the UE.
  • the UE In the case of originating sessions (i.e. session requests sent by the UE), the UE will recognise that a malfunction has occurred and perform re-registration. Re-registration may result in the UE being assigned to a new P-CSCF, following a P-CSCF discovery step.
  • terminating sessions i.e. session requests sent to the UE
  • the session request or ongoing session will be lost.
  • packet core network i.e. the network between the P-CSCF and the UE
  • notifications may be generated within the IMS and passed down to the packet core network, or the packet core network itself may detect that the P-CSCF has failed.
  • These procedures require the restoration to be performed outside of the IMS, which requires nodes in the packet core network to be adapted to handle the procedures, and may involve further latency.
  • redundant nodes may be provided which can “step in” for a failed P-CSCF.
  • IPSec data must be backed up frequently from the primary node.
  • a method in an IP multimedia subsystem, IMS, of a telecommunications network The loss of a secure association between a P-CSCF of the IMS and a user equipment, UE, served by the P-CSCF is detected, or a UE is relocated from a further P-CSCF to the first mentioned P-CSCF.
  • the first mentioned P-CSCF sends a reregistration request to the UE; receives a SIP REGISTER message from the UE; and performs P-CSCF registration with the UE including establishing a new secure association with the UE.
  • apparatus configured to operate as a Proxy Call Session Control Function, P-CSCF, in a telecommunications network.
  • the apparatus comprises a transceiver and a reregistration processor.
  • the transceiver is configured to communicate with user equipments, UEs.
  • the reregistration processor is configured to:
  • the apparatus configured to operate as a user equipment, UE.
  • the apparatus comprises a transceiver and a reregistration processor.
  • the transceiver is configured to communicate with a proxy call session control function, P-CSCF, of a telecommunications network.
  • P-CSCF proxy call session control function
  • the reregistration processor is configured to:
  • FIG. 1 is a signalling diagram showing a registration procedure in an IMS network
  • FIG. 2 is a signalling diagram showing an exemplary embodiment
  • FIG. 3 is a flowchart of the exemplary embodiment
  • FIG. 4 is a schematic diagram showing a P-CSCF and a UE according to an exemplary embodiment.
  • P-CSCF restoration procedure which can be performed mainly in the IMS, without involving the packet core network directly. It is further desirable to have a method which allows easier reallocation of a P-CSCF when such reallocation would not allow the security association from the old P-CSCF (or virtual instance of a cloud-based P-CSCF) to be transferred to the new P-CSCF (or new virtual instance).
  • a P-CSCF loses the security association with a UE, but otherwise continues to function normally.
  • a complete failure of a P-CSCF occurs, preventing the P-CSCF from continuing to serve the UE in any way.
  • handling of a UE is to be transferred from a first P-CSCF to a second P-CSCF, either in response to an error in the first P-CSCF, or for other reasons such as load balancing.
  • the P-CSCF(s) may be a virtual instance(s) of a cloud based P-CSCF.
  • the failure may be detected internally by the P-CSCF, e.g. when the P-CSCF attempts to process a message addressed to the UE or a message sent by the UE, or when the P-CSCF detects some circumstance which would result in loss of the secure association (e.g. change of IP address).
  • the S-CSCF may detect the failure of the P-CSCF due to the lack of acknowledgement of a message sent towards the UE.
  • the failure detection mechanisms disclosed in 3GPP TS23.380 v12.0.0 may be used. The nature of the failure detection does not particularly affect the performance of the methods of this disclosure.
  • a second P-CSCF will be selected to serve the UE.
  • This selection occurs within the IMS, e.g. by the S-CSCF, and may be based on current network traffic, the identity of the first P-CSCF, or any other suitable factor. This differs from the method of the current standards, in which the UE is notified of the failure by the packet core and then performs IMS registration procedures which will lead to selection of and registration with a new P-CSCF.
  • the result of the failure or transfer is that the UE is assigned to a P-CSCF which does not have a secure association with the UE.
  • this is the P-CSCF which the UE was originally assigned to
  • this is the second P-CSCF.
  • this will be referred to as the second P-CSCF through this description, but it should be noted that in the first case this may be the original P-CSCF (places where the methods differ if there is no change in P-CSCF will be noted).
  • the UE In order to restore the secure association, the UE is required to re-register with the P-CSCF. However, the UE is currently unaware of the failure.
  • the second P-CSCF sends a reregistration request to the UE. This prompts the UE to initiate a reregistration with the P-CSCF (which will be identified in the reregistration request at least as the sender of the request).
  • the UE does not perform any P-CSCF discovery steps, and no node of the packet core network is involved except to transfer the messages to the UE.
  • the first P-CSCF When the UE initially attaches to the first P-CSCF, the first P-CSCF generates a security token.
  • This token may be generated from values known to both the UE and the P-CSCF, e.g. the Ck, Ik, or RAND values used during authentication of the UE, or it may be generated from values known only to the P-CSCF (e.g. a random number) which are then sent to the UE over the secure connection.
  • the UE may provide a value for the generation of the security token over the secure association.
  • the token therefore represents a secret shared between the UE and the P-CSCF.
  • the first P-CSCF stores this token in some other node of the IMS, e.g. the S-CSCF or the HSS, so that it can be retrieved later in case of P-CSCF failure or transfer.
  • the second P-CSCF retrieves the security token from the other node of the IMS, and includes this security token within the reregistration request.
  • the UE will then attempt to authenticate the security token using the shared secret between the UE and the first P-CSCF, and will only proceed with the re-registration if the authentication succeeds.
  • the security token may be a quantity digitally signed using the private key of a public-private key pair associated with the first P-CSCF.
  • the UE may then authenticate the token by confirming that the digital signature is valid using the first P-CSCF's public key.
  • the UE may provide, for example upon initial attachment to the network, an indication that it supports the above method.
  • This indication may be explicit or implicit in some other communication (e.g. providing a security token may be used as an implicit indication that the method is supported).
  • the second P-CSCF may then determine whether the UE has provided such an indication, and the above method may only be used for UEs which support the method. For other UEs, the P-CSCF may fall back on existing standards.
  • FIG. 2 is a signalling diagram showing the signalling involved in the method
  • FIG. 3 is a flowchart showing the steps of the method at an abstracted level
  • FIG. 4 is a schematic diagram of a UE and P-CSCF configured to implement the method.
  • FIGS. 3 and 4 do not show the other nodes of the telecommunications network, as the method does not result in any changes to normal procedures at those nodes, and the skilled person could easily determine the actions at those nodes based on current standards.
  • Elements in dotted lines and/or italics represent the optional step of using the security token described above.
  • the P-CSCF 1000 comprises a transceiver 1001 , a reregistration processor 1002 , and optionally a secure association processor 1003 .
  • the UE 2000 comprises a transceiver 2001 , and a reregistration processor 2002 .
  • a UE in an originating network sends a SIP INVITE request to the UE in the home network (shown by the signalling 101 , 102 and 103 ).
  • the secure association processor determines that it has lost the secure association with the UE ( 104 , S 101 ). This may be due to a failure at the P-CSCF, or due to control being passed to the P-CSCF from a previous P-CSCF due to failure of the previous P-CSCF or by the network. Alternatively, failure of the previous P-CSCF may be detected by some other node of the IMS, and the remainder of the method may be triggered by this detection and the handover to the P-CSCF.
  • the reregistration processor of the P-CSCF retrieves the security token (from the S-CSCF in this example, 105 , 106 , S 102 ). The reregistration processor of the P-CSCF then causes the transceiver to send a reregistration request to the UE (including the security token if used, 107 , S 103 ). The UE receives the reregistration request via the transceiver (S 104 ), and the reregistration processor of the UE verifies the security token (if used, 108 , S 105 ).
  • the reregistration processor of the UE causes the transceiver to send a SIP REGISTER message to the P-CSCF, and performs registration with the P-CSCF ( 109 , S 105 , S 106 ).
  • the registration is shown in more detail in FIG. 1 .
  • the registration proceeds according to current standards, except that a P-CSCF discovery step and any preceding steps are unnecessary as the P-CSCF for the UE has already been assigned (i.e. the P-CSCF that sent the reregistration request).

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Computer Security & Cryptography (AREA)
  • Business, Economics & Management (AREA)
  • General Business, Economics & Management (AREA)
  • Telephonic Communication Services (AREA)
  • Mobile Radio Communication Systems (AREA)
US15/553,259 2015-02-27 2015-02-27 P-CSCF recovery and reregistration Active 2035-04-01 US10523720B2 (en)

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PCT/EP2015/054218 WO2016134791A1 (fr) 2015-02-27 2015-02-27 Récupération et réenregistrement de p-cscf

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11212323B2 (en) * 2019-07-04 2021-12-28 Deutsche Telekom Ag Infinity registration using session initiation protocol-based communication in a session initiation protocol-based network
US20230113082A1 (en) * 2021-10-13 2023-04-13 T-Mobile Usa, Inc. Proxy-call session control function (p-cscf) restoration
US20230217235A1 (en) * 2021-12-30 2023-07-06 T-Mobile Usa, Inc. Hss-based p-cscf restoration triggered by as

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10051017B2 (en) * 2016-12-28 2018-08-14 T-Mobile Usa, Inc. Error handling during IMS registration
WO2020212642A1 (fr) * 2019-04-16 2020-10-22 Nokia Technologies Oy Gestion de centre de données
US11950199B2 (en) 2019-04-24 2024-04-02 Telefonaktiebolaget Lm Ericsson (Publ) Network node and method performed therein for controlling transmission
US11343686B2 (en) * 2020-03-11 2022-05-24 Verizon Patent And Licensing Inc. Systems and methods for call session control function failover using dynamic routing techniques
US11632405B2 (en) * 2021-09-03 2023-04-18 T-Mobile Usa, Inc. Proxy-call session control function (P-CSCF) restoration

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070207805A1 (en) * 2004-08-13 2007-09-06 Pallares Lopez Miguel A Servers And Methods For Handover Between Two Serving Call Control Servers
US20080092226A1 (en) * 2006-10-12 2008-04-17 Motorola, Inc. Pre-registration secure and authenticatedsession layer path establishment
WO2008085010A1 (fr) 2007-01-11 2008-07-17 Samsung Electronics Co., Ltd. Procédé de réenregistrement dans l'ims et système correspondant
US20080182575A1 (en) 2007-01-30 2008-07-31 Motorola, Inc. Ims reliability mechanisms
US20090170512A1 (en) * 2007-07-05 2009-07-02 Oz Communications Inc. Maintaining IMS Registration While Disconnected from IP Bearer
US20100062767A1 (en) * 2006-10-24 2010-03-11 Nokia Siemens Networks Gmbh & Co. Method for re-assignment of s-cscf services to registered ims users of a home subscriber servers hss
US7746836B2 (en) * 2006-10-16 2010-06-29 Motorola, Inc. Method and apparatus for re-registration of connections for service continuity in an agnostic access internet protocol multimedia communication system
US20100165833A1 (en) * 2006-12-29 2010-07-01 Huawei Technologies Co., Ltd. Method, system, and network element for service processing after data of network element is invalid or network element fails
US20120082136A1 (en) * 2006-09-11 2012-04-05 Kddi Corporation P-cscf fast handoff for ims/mms architecture
US20130272253A1 (en) * 2010-11-30 2013-10-17 Koninklijke Kpn N.V. Dynamic Assignment of a Serving Network Node
US20130286843A1 (en) * 2010-12-03 2013-10-31 Nec Corporation Mobile communication method, gateway apparatus, mobility management node, and call session control server apparatus
WO2013174413A1 (fr) 2012-05-21 2013-11-28 Telefonaktiebolaget L M Ericsson (Publ) Procédé et appareil de gestion d'un échec p-cscf et de rétablissement de la connectivité
US20160380802A1 (en) * 2013-09-24 2016-12-29 Nec Corporation Methods and apparatuses for facilitating p-cscf restoration when a p-cscf failure has occurred

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070207805A1 (en) * 2004-08-13 2007-09-06 Pallares Lopez Miguel A Servers And Methods For Handover Between Two Serving Call Control Servers
US20120082136A1 (en) * 2006-09-11 2012-04-05 Kddi Corporation P-cscf fast handoff for ims/mms architecture
US20080092226A1 (en) * 2006-10-12 2008-04-17 Motorola, Inc. Pre-registration secure and authenticatedsession layer path establishment
US7746836B2 (en) * 2006-10-16 2010-06-29 Motorola, Inc. Method and apparatus for re-registration of connections for service continuity in an agnostic access internet protocol multimedia communication system
US20100062767A1 (en) * 2006-10-24 2010-03-11 Nokia Siemens Networks Gmbh & Co. Method for re-assignment of s-cscf services to registered ims users of a home subscriber servers hss
US20100165833A1 (en) * 2006-12-29 2010-07-01 Huawei Technologies Co., Ltd. Method, system, and network element for service processing after data of network element is invalid or network element fails
US9706019B2 (en) * 2006-12-29 2017-07-11 Huawei Technologies Co., Ltd. Method, system, and network element for service processing after data of network element is invalid or network element fails
USRE46361E1 (en) * 2007-01-11 2017-04-04 Samsung Electronics Co., Ltd IMS reregistration method and system therefor
WO2008085010A1 (fr) 2007-01-11 2008-07-17 Samsung Electronics Co., Ltd. Procédé de réenregistrement dans l'ims et système correspondant
US20080182575A1 (en) 2007-01-30 2008-07-31 Motorola, Inc. Ims reliability mechanisms
US20090170512A1 (en) * 2007-07-05 2009-07-02 Oz Communications Inc. Maintaining IMS Registration While Disconnected from IP Bearer
US20130272253A1 (en) * 2010-11-30 2013-10-17 Koninklijke Kpn N.V. Dynamic Assignment of a Serving Network Node
US20130286843A1 (en) * 2010-12-03 2013-10-31 Nec Corporation Mobile communication method, gateway apparatus, mobility management node, and call session control server apparatus
WO2013174413A1 (fr) 2012-05-21 2013-11-28 Telefonaktiebolaget L M Ericsson (Publ) Procédé et appareil de gestion d'un échec p-cscf et de rétablissement de la connectivité
US20160380802A1 (en) * 2013-09-24 2016-12-29 Nec Corporation Methods and apparatuses for facilitating p-cscf restoration when a p-cscf failure has occurred
US10148487B2 (en) * 2013-09-24 2018-12-04 Nec Corporation Methods and apparatuses for facilitating P-CSCF restoration when a P-CSCF failure has occurred

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11212323B2 (en) * 2019-07-04 2021-12-28 Deutsche Telekom Ag Infinity registration using session initiation protocol-based communication in a session initiation protocol-based network
US20230113082A1 (en) * 2021-10-13 2023-04-13 T-Mobile Usa, Inc. Proxy-call session control function (p-cscf) restoration
US11864265B2 (en) * 2021-10-13 2024-01-02 T-Mobile Usa, Inc. Proxy-call session control function (P-CSCF) restoration
US20230217235A1 (en) * 2021-12-30 2023-07-06 T-Mobile Usa, Inc. Hss-based p-cscf restoration triggered by as

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EP3262806A1 (fr) 2018-01-03
EP3262806B1 (fr) 2018-12-19
WO2016134791A1 (fr) 2016-09-01
US20180241784A1 (en) 2018-08-23

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